Tunisia is facing a huge and growing jihadist problem

Policemen guard the entrance of the Bardo museum in Tunis, Tunisia, Thursday, March 19, 2015, as a a blood stain is seen at right, a day after gunmen opened fire killing over 20 people, mainly tourists. Christophe Ena/AP The Islamic State has reportedly claimed responsibility for the terrorist attack at the Bardo museum in Tunis. The SITE Intelligence Group has obtained a 3-minute audio message, as well as a written transcript in Arabic, that are attributed to the organization. The audio message and the written copy were disseminated via Twitter.

The "blessed invasion" of "one of the dens of disbelief and immorality in Muslim Tunisia" was carried out by two "knights" from the "Caliphate," the Islamic State's representative says. The two terrorists are identified as Tunisians going by the aliases Abu Zakaria al Tunisi and Abu Anas al Tunisi.

"The brothers were able to lay siege to a malicious group from the citizens of the Crusader countries, who were deceived by the apostates, beautifying for them the land of Tunisia to be a hotbed for their disbelief and debauchery," SITE's translation of the Islamic State's message reads.

Most of the victims killed in the attack were foreign tourists, which accounts for the Islamic State's reference to the "Crusader countries." Twenty of the victims were visiting from Britain, Colombia, Germany, Italy, Japan, Poland, and Spain, according to press accounts. Three Tunisians, in addition to the two attackers, were also killed in the assault. Still others were wounded.

The attack is the most devastating strike against civilians in Tunisia since the April 11, 2002 bombing at the El Ghriba synagogue. Nineteen people were killed in that bombing, which was carried out by al Qaeda.

In more recent years, the jihadists have focused their operations mainly on Tunisia's security forces. For example, Al Qaeda in the Islamic Maghreb's (AQIM) Uqba bin Nafi Battalion killed four Tunisian security officers in February. Tunisian authorities said that 20 fighters took part in that assault.

Many Tunisian jihadists have gone off to fight for the Islamic State in Iraq and Syria. Those who have returned have fueled the chaos and violence in neighboring Libya.

The Islamic State has been building a presence in Tunisia, but it is not clear how many fighters loyal to Abu Bakr al Baghdadi's self-declared "caliphate" are located in the country. The Islamic State has been poaching from al Qaeda-allied groups, such as Ansar al Sharia and the Uqba bin Nafi Battalion, both of which are part of AQIM's network. ISIS militants. Screen grab

A statement issued last year declared that the Uqba bin Nafi Battalion's fighters had sworn allegiance to Baghdadi, but it quickly became apparent that the statement did not speak for the entire organization. A recent video from the group featured al Qaeda's leaders, and a statement from the jihadists made it clear that their leadership is still loyal to AQIM.

Some members of Ansar al Sharia Tunisia have also defected to the Islamic State. In December of last year, a Tunisian jihadist named Boubaker el Hakim appeared in a pro-Islamic State video that was posted online. El Hakim also claimed responsibility for the assassinations of two Tunisian opposition politicians during the video.

In July 2013, Tunisian authorities implicated el Hakim in the assassinations, which the officials said were ordered by the leader of Ansar al Sharia Tunisia, Abu Iyad al Tunisi. Tunisian officials pointed to el Hakim's jihadist experience in Iraq as one of the reasons he was considered so dangerous. [See LWJ report, Tunisian government alleges longtime jihadist involved in assassinations.]

Tunisian officials have expressed alarm at the growing jihadist problem. Earlier this week, as reported by Tunisia Live, the Interior Ministry announced "the arrest of 22 militants working in four alleged terrorist cells recruiting young Tunisians to fight in Libya." The government also said that "an additional 10 other militants were also arrested while attempting to cross into Libya to join militant groups."

In February, according to Reuters, Tunisian officials "arrested 32 militant Islamists," who were said to be planning "spectacular" attacks. Some of them had fought in Syria.